Oracle no privileges on tablespace USERS

You are granting the privileges to the incorrect user.

The schema owner i owns the table, and is therefore the user that needs to be granted the relevant permissions on the tablespace.

It is because no privilege on tablespace. Grant tablespace quota to the user to fix this:

SQL> alter user <your username> quota unlimited on tablespace_name;

SQL> GRANT UNLIMITED TABLESPACE TO <your username>;

Detailed on ora-01950